1. Field of the Invention
The present invention relates to locking devices that completely encompass a gas cap attached to a spout. In particular, the present invention relates to locking devices that prevent an intruder from frictionally engaging the cap with the locking device to turn the cap to an open position.
2. Description of the Prior Art
As fuel costs increase, pilferage and siphoning fuel from vehicle fuel tanks increases. There are various methods in the prior art that try to stop thieves from siphoning fuel. The vehicle may be placed inside an enclosure or building, but this may not always be possible, as in the case of a semi-tractor on a cross-country run. An anti-siphon ring in the neck of the fuel tank is another method, but this ring can be pushed through by a metal shaft, such as a tire jack handle. A locking gas cap is another method but there is always the difficulty of finding the exact fit for the particular fuel tank spout.
The Mallock U.S. Pat. No. 2,294,922, shows a locking device that completely encompasses the fuel cap. The locking device, however, can be used only with the particular cap, being shaped to conform with the fuel cap, and the fuel cap must exactly fit the particular spout, resulting in the same problem of locking gas caps mentioned previously. Further, the locking device has anti-friction rollers 19 and a spring spider 18 to prevent frictional engagement of the fuel cap with the locking device, adding an extra cost. In addition to the extra cost, this arrangement has the disadvantage that the anti-friction rollers and spring spider are susceptible to freezing in place during the winter, losing their effectiveness.
3. Summary of the Invention
The present invention includes a locking device that completely encompasses a fuel cap and a portion of a fuel tank spout. The locking device has a main body that includes first and second portions hingedly connected with each other. The portions have corresponding mating surfaces surrounding a depression. When the mating surfaces are in contact the depressions form a cavity that is large enough to completely encompass the cap and a portion of the spout including a ring that is firmly engaging the spout.
A radial inwardly extending flange defines an opening to the cavity which is sufficiently large to accomodate most spout diameters. When a thief tries to pull up on the main body to frictionally engage the fuel cap and turn it to an open position by turning the main body, the flange will engage the ring preventing such engagement.
The cavity is also preferably taller than the exposed portion of the spout, thus preventing a thief from pushing the main body down into frictional engagement with the top of the fuel cap to turn it to open position.
Suitable means are provided for locking the hinged portions together. Thus, the hinging portions may have two lugs integral with the first and second hinging portions, the lugs having apertures which will receive a padlock thereby holding the first and second hinging portions in a closed position.